Consolidated Statement of Changes in Shareholders' Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance at Dec. 31, 2021	$ 27,363	$ 1,976	$ 504	$ 10,787	$ 25,238	$ (1,133)	$ (10,009)
Beginning balance (shares) at Dec. 31, 2021			503,880,000
Treasury stock, beginning balance (in shares) at Dec. 31, 2021							137,897,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	604				604
Other comprehensive income (loss)	(1,565)					(1,565)
Cash dividends declared:
Common stock dividends	(209)				(209)
Preferred stock cash dividends	(20)				(20)
Common stock awards exercised	66			(11)			$ 77
Common stock awards exercised (in shares)							(1,132,000)
Other	(15)			(14)	(1)
Ending balance at Mar. 31, 2022	$ 26,224	1,976	$ 504	10,762	25,612	(2,698)	$ (9,932)
Ending balance (shares) at Mar. 31, 2022			503,880,000
Treasury stock, ending balance (in shares) at Mar. 31, 2022							136,765,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.57
Beginning balance at Dec. 31, 2021	$ 27,363	1,976	$ 504	10,787	25,238	(1,133)	$ (10,009)
Beginning balance (shares) at Dec. 31, 2021			503,880,000
Treasury stock, beginning balance (in shares) at Dec. 31, 2021							137,897,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,041
Other comprehensive income (loss)	(3,135)
Cash dividends declared:
Common stock dividends	(651)
Preferred stock cash dividends	(76)
Ending balance at Sep. 30, 2022	$ 25,648	1,976	$ 504	10,760	26,552	(4,268)	$ (9,876)
Ending balance (shares) at Sep. 30, 2022			503,880,000				135,912,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 1.77
Beginning balance at Mar. 31, 2022	$ 26,224	1,976	$ 504	10,762	25,612	(2,698)	$ (9,932)
Beginning balance (shares) at Mar. 31, 2022			503,880,000
Treasury stock, beginning balance (in shares) at Mar. 31, 2022							136,765,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	747				747
Other comprehensive income (loss)	(989)					(989)
Preferred stock redeemed	0
Cash dividends declared:
Common stock dividends	(210)				(210)
Preferred stock cash dividends	(35)				(35)
Common stock acquired	0
Common stock awards exercised	29			(5)			$ 34
Common stock awards exercised (in shares)							(505,000)
Other	1				1
Ending balance at Jun. 30, 2022	$ 25,767	1,976	$ 504	10,757	26,115	(3,687)	$ (9,898)
Ending balance (shares) at Jun. 30, 2022			503,880,000
Treasury stock, ending balance (in shares) at Jun. 30, 2022							136,260,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.57
Net income	$ 690				690
Other comprehensive income (loss)	(581)					(581)
Common stock dividends	(232)				(232)
Preferred stock cash dividends	(21)				(21)
Common stock awards exercised	25			3			$ 22
Common stock awards exercised (in shares)							(348,000)
Ending balance at Sep. 30, 2022	$ 25,648	1,976	$ 504	10,760	26,552	(4,268)	$ (9,876)
Ending balance (shares) at Sep. 30, 2022			503,880,000				135,912,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.63
Beginning balance at Dec. 31, 2022	$ 25,191	1,976	$ 504	10,730	27,028	(3,711)	$ (11,336)
Beginning balance (shares) at Dec. 31, 2022			503,880,000
Treasury stock, beginning balance (in shares) at Dec. 31, 2022	154,855,475						154,855,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 549				549
Other comprehensive income (loss)	439					439
Cash dividends declared:
Common stock dividends	(212)				(212)
Preferred stock cash dividends	(23)				(23)
Common stock acquired	(1,262)						$ (1,262)
Common stock acquired (shares)							13,647,000
Common stock awards exercised	69			(6)			$ 75
Common stock awards exercised (in shares)							(1,085,000)
Other	(1)						$ (1)
Other (shares)							1,000
Ending balance at Mar. 31, 2023	$ 24,750	1,976	$ 504	10,724	27,342	(3,272)	$ (12,524)
Ending balance (shares) at Mar. 31, 2023			503,880,000
Treasury stock, ending balance (in shares) at Mar. 31, 2023							167,418,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.63
Beginning balance at Dec. 31, 2022	$ 25,191	1,976	$ 504	10,730	27,028	(3,711)	$ (11,336)
Beginning balance (shares) at Dec. 31, 2022			503,880,000
Treasury stock, beginning balance (in shares) at Dec. 31, 2022	154,855,475						154,855,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 1,734
Other comprehensive income (loss)	666
Cash dividends declared:
Common stock dividends	(628)
Preferred stock cash dividends	(84)
Ending balance at Sep. 30, 2023	$ 23,621	1,976	$ 504	10,735	27,993	(3,045)	$ (14,542)
Ending balance (shares) at Sep. 30, 2023			503,880,000				195,296,000
Treasury stock, ending balance (in shares) at Sep. 30, 2023	195,296,131
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 1.95
Beginning balance at Mar. 31, 2023	$ 24,750	1,976	$ 504	10,724	27,342	(3,272)	$ (12,524)
Beginning balance (shares) at Mar. 31, 2023			503,880,000
Treasury stock, beginning balance (in shares) at Mar. 31, 2023							167,418,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	763				763
Other comprehensive income (loss)	14					14
Cash dividends declared:
Common stock dividends	(203)				(203)
Preferred stock cash dividends	(37)				(37)
Common stock acquired	(1,060)						$ (1,060)
Common stock acquired (shares)							14,773,000
Common stock awards exercised	34			5			$ 29
Common stock awards exercised (in shares)							(415,000)
Other	(57)				(57)
Other (shares)							2,000
Ending balance at Jun. 30, 2023	$ 24,204	1,976	$ 504	10,729	27,808	(3,258)	$ (13,555)
Ending balance (shares) at Jun. 30, 2023			503,880,000
Treasury stock, ending balance (in shares) at Jun. 30, 2023							181,778,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.63
Net income	$ 422				422
Other comprehensive income (loss)	213					213
Common stock dividends	(213)				(213)
Preferred stock cash dividends	(24)				(24)
Common stock acquired	(1,010)						$ (1,010)
Common stock acquired (shares)							13,843,000
Common stock awards exercised	29			6			$ 23
Common stock awards exercised (in shares)							(327,000)
Other
Other (shares)							2,000
Ending balance at Sep. 30, 2023	$ 23,621	$ 1,976	$ 504	$ 10,735	$ 27,993	$ (3,045)	$ (14,542)
Ending balance (shares) at Sep. 30, 2023			503,880,000				195,296,000
Treasury stock, ending balance (in shares) at Sep. 30, 2023	195,296,131
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.69